Watch timing apparatus



, Jan. 12, 1943. E. NORRMAN WATCH TIMING APPARATUS {Failed Ma y 12., 1936 E'Sheets-Sheei: 1.

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11mm WATCH .7 AMPLIFIER AMPLIFIER 22 INVENTOR ERNST N OERMQN ATTORNEYS Jan. 12, 1943.

. Filed May 1 2, 1936- 5 S lie ets-Sheet 2 18 TESTED WATCH @@i3.4

INVENTOR EPA/57' NOERMAW m. m E RH. nm M A MA MASTER WATCH ATTORNEYS Jan. 12, 1943. E. NORRMAN' WATCH TIMING APPARATUS Filed May 12, 1956 5 Sheets-Sheet 3 V INVENTOR I FP VJT NOPEMfi/V ATTO RN EYS Patented Jan. 12, 1943 UNITED. STATES PATENT OFFICE WATCH TIMING APPARATUS Ernst Norrman, Chicago, n1.

Application May 12, 1930, Serial No. 79,263 Claims. (01. 73-52) The present invention relates to an improved apparatus for testing chronometers as compared with a master chronometer.

In the course of the manufacture of chronometers of all kinds various adjustments are necessary if accuracy under the varying conditions is to be secured. This is particularly true of watches which, it the maximum accuracy is to be maintained must be adjusted for changes in temperature and for the changes in the position in which they may be carried. For example, a

watch can be so adjusted that it will vary less than ,five seconds per day when'held in any one of five positions. vWhen it is noted that the adjustment to such accuracy requires repeated testing of the running and repeated stoning of the bearings until bythe cut and-{try method the a-ble delay in filling orders, particularly special orders.

If, for example, it is possible to read the time of the watch to an accuracy of only one second then a considerable period is necessary to detect a variation which should be corrected, but if .the watch can be read to an accuracy of 1/1000 of a second a correspondingly shorter period of time is suflicient to determine a similar variation.

Two types of watch timing devices have been developed for the use of watch manufacturers and watch repairing jewelers. In one type a reference member, usually a rotatable dial, is drivenunder control from a tuning fork or other accurate standard. Devices of this .type are very satisfactory in use but expensive to manufacture and for many the cost is prohibitive. In another type a' rotatable dial is driven at an approximately constant speed and means is provided for making comparison between a master watch and the dial and also between the dial and the watch to be tested. Usually the dial is "rein-med from time to time, that is to say, the necessary adjustment is made to bring a zero of the dial opposite an index member. In the use of these devices the accuracy obtained depends too much on the human equation. The additional step of reiraming the dial from time to time is an inconvenience and through carelessness or inadvertence is often neglected with consequent error in the readings of the watch under test.

The present invention has for an object to provide a watch timing apparatus wherein the reference member, usually a rotatable dial, can be driven from a suitable motor running at a substantially constant speed but under control from a master watch to provide the desired accuracy.

Another object is to make provision whereby a pocket watch can be efiectively used asa standard to control the reference member.

The nature and objects of the invention-will be better understood from a description of illustrative embodiments thereof for the purpose of which description reference should be had to the accompanying drawing forming a part hereof and in which- K Figure 1 is a partially diagrammatic plan view of an apparatus embodying the invention,

Fig. 2 is a sectionalview of the same taken on the line 2-2 of Fig. 1,

Fig. 3 is a detail view taken on the line 3-3 of Fig. 1 showing a device for eliminating the response to alternate ticks oi. the watch when desired.

Fig. 4 is a. circuit diagram indicating connections whereby an alternating current source may be utilized and showing one of the amplifier circuitsindetail,

Fig. 5 is a plan view largely diagrammatic show-.

ing another embodiment of the invention applicable to watch timing mechanism of the type shown in Fig. 1- but here shown as applied to a recording watch timing apparatus,

Fig. 6 is a view in elevation of the embodiment shown in Fig. 5,

Fig. 7 is a view of a positively acting means for rotatably shifting the diaion its shaft,

Fig. 8 is a plan view of the same, and

Fig. 9 isa diagrammatic viewof anotherembodiment.

The illustrative apparatus shown principally in Figs. 1 and 2 and to be described for the purposes or illustration comprises aninstrument 5 having a rotatable graduated dial 6 which maybe-mounted on the shaft of a motor 1 within the instrument casing. The top oi. the casing is formed with a window 9 and at the center thereoian index 10 for framing the reference dialwlth.

respect to the ticks of the master watch. Asomewhat similar window II is provided having, if desired, a central index l2 for studying the action or the watch to be tested.

The tick responsive devices such as microphones l5, iii are provided having sultable'supports to receive the master'watoh l1 and the watch to be tested It.

The rotatable dial 8 may be made of translucent material with black graduation marks and numerals whereby it can be illuminated from beneath for the purposes of reading. This arrangement is in some respects more practical than an arrangement in which the disk is opaque and iliuminated on its face. The dial as shown has one hundred graduations divided into flve groups with similar markings to correspond to the five ticks of a.watch. For watches with a different number of ticks a correspondingly difi'erent dial may be substituted.

As the microphone i5 responds to the ticks of the master watch l1, the impulse is amplified and shortened to provide a momentary current for illuminating the neon flash lamp is beneath the transparent dial 8 at the window 3.

Provision is made for relative adjustment be-\ tween the rotating dial and the index l0 whereby the zero of the dial may be brought into registration with the index 10. This adjustment for framing may conveniently be made by rotating the motor as a whole within the casing. For this purpose the motor is shown as mounted on a base 2| having gear teeth on its periphery which are engaged by a pinion 22 on a vertical shaft 23 to the top of which is secured a suitable thumb wheel 24.

As the microphone i6 responds to the ticks of the watch to be tested, l3, the impulse is amplitied and shortened to provide a momentary current for illuminating the neon lamp or lamps 25 beneath the dial 6 at the window II. An adjustable hand 26 which may be operated by a. thumb wheel 21 is provided at the window H and can be adjusted to show the position of a zero of the dial. The window Ii is so wide that at least one 0 is always to be seen.

It will be seen that the arrangement described makes provision for framing the dial relative to the index and then adjusting the hand 23 to the zero as illuminated from the watch to be tested. Furthermore, refraining is possible in the event of a shift of the dial relative to the index for the master watch during which reframing the relation between the index "I and the hand 26 is maintained. In other words, the hand 26, which also is an index, in its adjusted position is fixed relative to the index Hi.

The positions of the windows 3 and II may be selected with relation to the number of zero positions on the dial and the angular position between them, but this is not necessary for reasons which will be seen upon analysis of the operation of the device.

For the purposes of illustration the watch supports may be carried by ball and socket joints on fixed bases, the ball and socket connection permitting movement of the support to any oi the desired positions in which the running of the watch is to be tested. Ordinarily the master chronometer or watch support need not be adjustable for obvious reasons.

The watch holder is preferably carried by a sponge rubber or other suitable packing or damping element in order to avoid the effect of extraneous noises and jars which might otherwise excite the microphone button. This microphone is sensitive to the ticks of the watch but insensitive to room noises or jars. Across each microphone circuit a rheostat for adjusting its sensitivity may be connected.

The electrical circuit of each of the amplifiers indicated at 30 and 3| in Fig. 1 and shown in detail in the electrical diagram, Fig. 4 is in many respects similar to the circuit shown in my copending applications, Ser. No. 670,267, filed May 10, 1933, now Patent No. 2,058,616 granted October 27, 1936, and Ser. No. 63,858 flled February 14, 1936 which matured into Patent No. 2,064,559, granted December 15, 1936, and reissued as Patent N0. Re. 21,355 granted February 13, 1940 and includes both amplifying and impulse shortening circuits.

The first two stages of amplification including the input transformer 35 and amplifier tubes 36 and 31 may be arranged in accordance with standard practice for a resistance coupled amplifier.. The third vacuum tube 38 employs a special circuit which may be called the time limiting circult. In the particular circuit shown the tubes 36 and 31 may be #57 tubes and the tube 33 a thyratron tube now known as a #885 tube.

The operation of the time limiting circuit is as follows. When the condenser 40 has been charged the circuit is at equilibrium, no current flowing in any part. when an impulse in a positive direction is impressed on the control grid of the tube 38, this tube will pass current and the condenser 40 discharges through the primary of the transformer 42.- The time it takes for the condenser to discharge depends on its capacity and on the impedance of the primary winding of the transformer 42 and also on the plate impedance of the tube. By choosing the proper constants, impulses of very short duration may be obtained. After the condenser 40 is partially discharged the plate voltage of the tube drops below the critical point on account of the high value of the resistor 4|, through which the condenser 40 is slowly charged and the current through the tube ceases.

By this circuit arrangement impulses (A. C. or D. C.) of a relatively long duration will give output impulses of very short duration of the order of 1/ 1000 or 1/ 10,000 of a second. The condenser 40 is slowly charged through the resistor 4|, during the silent interval between the impulses and so the cycle repeats itself.

The lamps 25 herein shown are neon lamps suitably designed to provide the desired instantaneous flash to illuminate the dial. when the condenser 40 discharges through the primary of transformer 42 the current induced in the secondary energizes the lamp 2!.

If desired earphones 4! may be added to the circuit for the watch to be tested to make audible the tick induced impulse. In the circuit shown the output of tube 31 acting through transformer 44 will be sufilcient for the earphones.

It is seldom that the time interval between two successive ticks is exactly the same, perhaps because the escapement is not perfectly centered. For this reason if the flash lamps 2! are lighted in response to each tick of the watch the device will show an apparent hunting, the range of which will indicate the extent to which the escapement is inaccurately centered and whether correction is necessary. For timing purposes it is preferable to avoid this hunting and this may be accomplished by a suitable provision whereby the lamps 25 are energized by alternate ticks only.

The power for the amplifying circuit may conveniently be supplied from an A. C, current which also operates the motor of the reference dial. In the arrangement illustrated the A. C. line current passes through the primary 48a of a transformer 46 which transformer through a aaoaaoa secondary winding supplies current to the filaments of the tubes. A rectifier tube it provides direct current to the +3 circuit. The arrangements giving the +3, and -C voltages are conventional and are sufiiciently illustrated in the drawings. v

A positive method of insuring response to only alternate ticks of the watch thereby to prevent the appearance of hunting may be provided in accordance with the arrangement shown in Figs. 1 and 3. As there shown a commutator 50 which is connected to the motor shaft by gearing and 52 to rotate once during an even number of ticks of the watch. In the arrangement indicated, assuming a dial 5 divided into five similar sections for a five tick watch the gearing ratio may be 4 to 5. This commutator is provided with an annular conducting section 53 and another section 54 which is divided into an even number of conducting and non-conducting sections to correspond to the number of ticks during one rotation, four being shown in the arrangement shown. A pair of brushes 55, 56 connected in one of the leads from the amplifier 30 to the lamps 25 is arranged to bear on thecommutator. These brushes may be moved laterally by switch handle 51 to bear on the continuous conducting portion 53 when it is desired to obtain responses from all ticks of the watch for the purposes of observing the operation and relation of the ticks at both ends of the swing of the balance wheel. When the watch is examined for timing and response from alternate ticks is desired, the brushes are moved laterally so that at least one brush bears on the segmented portionot the armature. A similar device for eliminating response to alternate ticks of the master watch is indicated at 50', 5| in Fig. 1.

The arrangements above described are substantially equivalent to the arrangement shown and described in my copending application, Ser. No. 63,858 with certain substitutions and improvements. In accordance with the present invention means is provided whereby after the motor is once started and the reference member framed, the dial may be maintained in synchronism with the master watch, thereby avoiding the necessity for refraining the dial to compensate for such drift as results from inaccuracy of the speed of the motor. This provides the advantages of an accurate reference member heretofore attained by the use of a tuning fork or other equivalent standard but at considerably less expense.

In one embodiment of the invention shown principally in Figs. 1 and 2 the dial is'yieldably connected to the motor shaft as by means of a friction connection and provision is made whereby the dial can be rotated relative to the shaft to make correction for the lead or lag of the dial with respect to the master watch used as a standard.

In the embodiment of the invention shown principally in Figs. 5 and 6 provision is made whereby the motor is mounted on a rotatable base and provision is made for rotating the base of the motor automatically under control of the master watch to compensate for lead or lag of the dial with respect to the master watch used as a standard.

In the embodiment shown in Figs. 1' and 8 another arrangement is provided in which the dial is rotated on its shaft to compensate for lead or lag.

Referring more particularly to the embodiment shown principally in Figs. 1 and 2 and in the electrical diagram of Fig, 4, the dial 6 is carried by a sleeve rotatable on the motor shaft BI and connected thereto by low resistance friction clutch 62 which ordinarily causes the dial to rotate with the motor shaft but yieldably so to permit corrective rotation of the dial relative to the motor shaft. In the particular embodiment shown in Figs. 1 and 2 the corrective movement is effected by an electromagnet 63 energized in response to ticks of the master watch and cooperating with an armature 64 keyed to the sleeve 60. The electromagnet 63 is arranged to be energized from the master watch. The particular shape of the armature having parallel walled slots 64' and wide poles is particularly satisfactory and has been developed as the result of experiment.

A switch 65 is provided to connect either the electromagnet 63 or the lamp 19 in the circuit from the master watch amplifier it. By this arrangement the lamp I9 is energized from the master watch to permit framing the dial by hand, and when the switch 65 connects the magnet the framing and correction is made automatically with the master watch. It will be noted that the magnet 63 will be energized either upon each tick of the master watch or preferably each alternate tick, the switch 51' ordinarily oeing positioned to cause alternate ticks of the watch to be effective. It has been discovered in actual operation that the electromagnet 63 can be sufilciently energized by the circuit shown in the diagram of Fig. 4 to move the armature 64 a necessary amount to synchronize the dial 6 with the master watch even when the motor I because of the fluctuations of the operating current lags or leads by a substantial amount. Obviously the current can be further amplified if necessary.

In the arrangement shown in Figs. 5 and 6, a rotatable disk 68 is driven at a substantially constant speed by a motor 69. The 'motor is mounted on a :otatable base which is provided with a gear wheel 10 and means is provided for rotating the motor base to compensate for the lead or lag of the dial due to variations of speed of the motor. The means for rotating the motor base which obviously gives an additional rotation to the disk which may be either additive or subtractive is shown as comprising a ratchet mechanism having an arm 13 which is constantly oscillated and *arries a double pawl 14 in operative engagement with a pinion "l5 meshing with the gear 10. The arm 13 may be actuated in any suitable manner. For purposes of disclosure it is shown as connected by a link 16 with a crank 11 on a shaft journaled in a bracket 18 which is shown as driven from the motor shaft at by beveled gearing 8| and worm and wheel gearing 82. The double pawl-is moved to the right or left, Fig. 5, by magnets 83 and. 84 to cause additive or subtractive rotation of the motor base, as the dial lags or leads with respect to the master watch. It will be noted that when the dial leads with respect to the master watch the electric circuit will be momentarily closed through a conductor point 86, conductor plate and magnet 84, thereby moving pawl 14 (if it has not already been moved in that direction) to engage the pinion 15 to cause subtractive rotation of the motor base and when this subtractive movement has over-compensated so that the dial lags by a predetermined amount another electric circuit will be closed through a conductor point 86, conductor plate 8I and magnet to reverse, the position of pawl 14 and cause additive rotation of the motor base.

This arrangement has the advantage that it is constantly operative without providing an inoperative zero position. The magnets 83, 84 may be energized from or under the control of any de-' tector circuits which indicate the lag or lead of is closed in response to a tick of the watch under test, a spark passes from a projecting pin 86 through the record strip or paper 85 to the conductor plate 81. A record of the performance of the watch is thus made on the record strip. In order to provide the necessary control of the double pawl 14, two additional conductor plates 80, 8I are provided, these plates being insulated from the plate 81 and from each other.v When an electrical current passes from a projection 86 to one of the plates 80, 8i, it will close a circuit through one ofthe electromagnets 83, 88 to determine the direction of the corrective movement of the ratchet mechanism asoperating to rotate the motor base. By following the electrical circuits, it will be seen that an impulse from either a master watch amplifier or a tested watch amplifier will lead current to the contact disk 82 through contact brush 83 and therefore to the disk 68 and to both projections 86 thereof. The return circuits however are so connected that if the electrical impulse comes from the tested watch amplifier, the current will flow to the plate 81 and mark the record strip 85. If the electrical impulse comes from the master watch it will pass from projection 88 to one of the plates 80, 8| and through the corresponding electromagnet without marking the paper.

It is, of course, necessary to pass the record strip between the disk 68 and the plate 81 but not between the disk and the plates 80, 8|. The passage of the paper under the plate 81 and over the plates 80, Si is indicated in Fig. 6.

In Fig. 9 is shown another arrangement for the detector circuits which detect the lag or lead of the rotatable dial with respect to the master watch. As here shown a dial 85 designed to rotate one revolution for each operative tick of the master watch carries two semi-circular conductor elements 86, 81 which are insulated from each other and engaged by a contact brush 88. The conductor element 86 is electrically connected to acontact ring 89 engaged by abrush I00 which is connected to energize one of the control magnets I M and Ill. The conductor element 81 is electrically connected to a contact ring I02 engaged by a brush I08 which is connected to energize the other of the control magnets.

When an impulse from the master watch amplifier passes through the brush 88, the brush will be in engagement with one of the two conductor segments to energize the corresponding control magnet or it will be in contact with the insulation 88' between the segments. If the brush 88 is incontact with the insulation 88 no corrective action of the electromagnets will take place but when there is a lead or lag of a predetermined amount, contact between the brush 88 and one'of the conductor segments will cause closing of the corresponding electric circuit and a corresponding corrective action.

In the arrangement shown in Figs. 7 and 8, the dial I05 is rotated on its shaft I06 by a mechanism of the pin and star wheel type. The dial is controlled by any suitable arrangement such, for example, as that shown in Fig. 5 whereby one magnet is energized at intervals if the disk lags in its rotation, and whereby the other magnet is energized momentarily if the rotation of the disk leads. So far as these magnets are concerned they perform substantially the same function as the magnets 83 and 88 of the arrangement shown in Fig. 5. In operation of this corrector mechanism, the bracket I08 rotates with the sleeve I01 and the disk I05, and during each rotation the wheel II2 will engage the rocking member 5 to rotate the shaft I08 and worm H0 in one direction or the other. Since the worm wheel III is fast on shaft I06 such rotation of the worm H0 will cause rotation of the disk I05 on the shaft I06 to correct for lead or lag.

The foregoing particular description is illustrative merely and not intended as defining the limits of the invention. 1

I claim:

1. An apparatus of the character described comprising a motor having a base rotatable about the axis of the motor shaft, a rotatable dial driven by the motor shaft, a tick responsive device adapted to respond to ticks of a master watch, and means responsive to a lack of synchronism between the rotation of the dial and the ticks of the master watch for rotating the motor base to make correction for the lack of synchronism.

2. An apparatus of the character described comprising a motor having a base rotatable about the axis of the motor shaft, a rbtatable dial driven by the motor shaft, a tick responsive device adapted to respond to ticks of a master watch, an electricalcircuit arranged to be closed in response to the ticks of the master watch when the rotatable dial leads with respect to the master watch by a predetermined amount and means actuated by the electrical circuit to rotate the motor in a direction opposite to the direction of rotation of the dial to compensate for the lack of synchronism.

3. An apparatus of the character described comprising a motor having a base rotatable about the axis of the motor shaft, a rotatable dial driven by the motor shaft, a tick responsive device motor in the same direction as the direction of rotation of the dial to compensate for the lack of synchronism.

4. An apparatus of the character described upon lack of comprising a motor having a base rotatable about the axis of the motor shaft, a rotatable dial driven by the motor shaft, ratchet mechanism for rotating the motor base, a tick responsive device adapted to respond to ticks of the master watch, and an electrical circuit adapted to be closed synchronism between the rotation of the dial and. the ticks of the master watch connected to control mechanism to make correction for such lack of synchronism.

5. An apparatus ofthe character described comprising a motor having a base rotatable about the axis of the motor shaft, a rotatable dial driven by the motor shaft, ratchet mechanism for rotating the motor base, a tick responsive device adapted to respond to ticks of the master watch, an electrical circuit arranged to be closed when the dial leads with respect to the master watch and controlling the ratchet mechanism to cause rotation of the motor base in a direction opposite to the direction of rotation of the dial, and a second electrical circuit arranged to be closed when the dial lags with respect to the master watch and controlling the ratchet mechanism to cause rotation of the motor base in the same direction as the .direction of rotation of the dial.

, 6. An apparatus of the character described comprising a shaft driven at a substantially constant speed, a dial mounted on said shaft normally to rotate therewith but capable of rotation relative thereto. a tick responsive device adapted to respond to ticks of the master watch, an electrical circuit arranged to be closed by said tick responsive device when the rotatable dial leads with respect to the master watch, a second electrical circuit arranged to be closed by said tick responsive device when the rotatable dial lags with respect to the master watch, and means controlled by said electrical circuits for rotating the dial with respect to said constantly driven shaft to compensate for the lack of synchronism between the rotatable dial and the master watch.

'7. An apparatus for timing watches comprising a reference member, means to drive the reference member at a substantially constant speed, a tick responsive device adapted to respond to the ticks of a master watch, means arranged to be controlled by the tick responsive device to modify the speed of movement of the reference member to synchronize the same with the master watch, and index member adjacent the reference member, a flash lamp positioned to illuminate he reference member adjacent the index member, a second tick responsive device adapted to respond to the ticks of a watch to be tested, and

the action of the ratchet means controlled by said second tick responsive device for energizing said flash lamp, said reference member and index member being mounted for relative adjustment to permit framing of the reference member with respect to the index member.

8. An apparatus for timing watches comprising a reference dial, means to rotate the reference dial at a substantially constant speed, a tick responsive device adapted to respond to ticks of a master watch, actuating means arranged to be connected for control by the tick responsive device operative to additionally control the move ment of the reference dial to synchronize the same with the master watch, an index member adjacent the reference dial, a flash lamp positioned to illuminate the reference dial adjacent the index member, means for energizing said flash lamp arranged to be connected for control by the tick responsive device, a second index member, a second lamp positioned to illuminate the reference dial adjacent the second index member, a second tick responsive device adapted to respond to ticks of a watch to be tested. and

means for energizing said second flash lamp arranged to be controlled by the second tick responsive device.

9. An apparatus of the character described comprising a casing having a window and an index adjacent said window, a rotatable graduated dial visible through said window, a motor in said casing to drive the dial at a substantially constant speed, a tick responsive device adapted to respond to ticks of a master watch, an electrical circuit. including an impulse shortening cir cuit, arranged to be closed in response to ticks of the master watch to modify the rotation of the dial, a tick responsive device adapted to respond to ticks of a watch to be tested, an electrical circuit, including an impulse shortening circuit, arranged to be closed in response to ticks of the watch to be tested, a flash lamp adjacent the dial arranged to be energized by the said last mentioned electrical circuit.

10. An apparatus of the character described comprising a rotatable reference member, an armature keyed to said reference member, an electromagnet positioned to cooperate with said armature, a shaft, a friction clutch arranged to drive said reference member from said shaft, the friction of said clutch being great enough so that ordinarily the reference member is driven without slippage from the drive shaft, but small enough so that the reference member may be rotated on said shaft by impulses imparted to the armature by said eiectromagnet, a tick responsive device and an electric circuit, including an impulse shortening circuit arranged to be energized by the tick responsive device and, in turn, to energize the electromagnet.

ERNST NORRMAN. 

